Firefox to block cross-site tracking by default in upcoming version

Anyone who isn’t an expert on the internet would be hard-pressed to explain how tracking on the internet actually works. Some of the negative effects of unchecked tracking are easy to notice, namely eerily-specific targeted advertising and a loss of performance on the web.

However, many of the harms of unchecked data collection are completely opaque to users and experts alike, only to be revealed piecemeal by major data breaches. In the near future, Firefox will — by default — protect users by blocking tracking while also offering a clear set of controls to give our users more choice over what information they share with sites.

Over the next few months, we plan to release a series of features that will put this new approach into practice through three key initiatives:

Improving page load performance

Tracking slows down the web. In a study by Ghostery, 55.4% of the total time required to load an average website was spent loading third party trackers. For users on slower networks the effect can be even worse.

Long page load times are detrimental to every user’s experience on the web. For that reason, we’ve added a new feature in Firefox Nightly that blocks trackers that slow down page loads. We will be testing this feature using a shield study in September. If we find that our approach performs well, we will start blocking slow-loading trackers by default in Firefox 63.

Removing cross-site tracking

In the physical world, users wouldn’t expect hundreds of vendors to follow them from store to store, spying on the products they look at or purchase. Users have the same expectations of privacy on the web, and yet in reality, they are tracked wherever they go. Most web browsers fail to help users get the level of privacy they expect and deserve.

In order to help give users the private web browsing experience they expect and deserve, Firefox will strip cookies and block storage access from third-party tracking content. We’ve already made this available for our Firefox Nightly users to try out, and will be running a shield study to test the experience with some of our beta users in September. We aim to bring this protection to all users in Firefox 65, and will continue to refine our approach to provide the strongest possible protection while preserving a smooth user experience.

Mitigating harmful practices

Deceptive practices that invisibly collect identifiable user information or degrade user experience are becoming more common. For example, some trackers fingerprint users — a technique that allows them to invisibly identify users by their device properties, and which users are unable to control. Other sites have deployed cryptomining scripts that silently mine cryptocurrencies on the user’s device. Practices like these make the web a more hostile place to be. Future versions of Firefox will block these practices by default.

Why are we doing this?

This is about more than protecting users — it’s about giving them a voice. Some sites will continue to want user data in exchange for content, but now they will have to ask for it, a positive change for people who up until now had no idea of the value exchange they were asked to make. Blocking pop-up ads in the original Firefox release was the right move in 2004, because it didn’t just make Firefox users happier, it gave the advertising platforms of the time a reason to care about their users’ experience. In 2018, we hope that our efforts to empower our users will have the same effect.

How to Manually Enable the Protections

Do you want to try out these protections in Firefox Nightly? You can control both features from the Firefox Nightly Control Center menu, accessible on the left-hand side of the address bar. In that menu you’ll see a new “Content Blocking” section. From there, you can:

Enable the blocking of slow-loading trackers or cross-site tracking through third-party cookies by clicking “Add Blocking…” next to the respective option.

In the “Content Blocking” preferences panel:

Click the checkbox next to “Slow-Loading Trackers” to improve page load performance.

Click the checkbox next to “Third-Party Cookies” and select “Trackers (recommended)” to block cross-site tracking cookies.

You can disable these protections by clicking the gear icon in the control center and unchecking the checkboxes next to “Slow-Loading Trackers” and “Third-party Cookies”.